Study of polarization-maintaining photonic crystal fibers with zero birefringent temperature sensitive coefficient

The factors that affect the temperature sensitivity of typical polarization-maintaining photonic crystal fibers (PM-PCF) are analyzed. By using the finite elements method, the influence of temperature on the birefringence of the typical solid core PM-PCF is studied, which mainly includes thermo-optic effects and thermal expansion. The results show that the thermo-optic effects can be neglected and the temperature sensitivity of birefringence can be represented only by a polynomial function of the center distance of adjacent air holes Λ under the working temperature from -150℃ to 150℃. The birefringence increases with Λ and becomes zero at Λ=5.16 μm. The compact hybrid Sagnac interferometer is used to measure the birefringence of five PM-PCF samples with different Λ under different temperatures. The experimental results conform well to the simulation.